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[TowerTalk] Rebar In Tower Base

To: <towertalk@contesting.com>
Subject: [TowerTalk] Rebar In Tower Base
From: K7LXC@aol.com (K7LXC)
Date: Fri, 3 Apr 1998 10:44:09 EST
In a message dated 98-04-01 12:48:24 EST, rudder1@ibm.net writes:

> The Rohn 25G is rated up to 40 foot self supporting depending on wind
>  zone and wind loading per the Rohn catalog.  The drawing for the self
>  supporting base specifies rebar on 12 inch centers in a 4 x 4 x 4 base
>  regardless of height or wind load.  The base section must be either the
>  bottom tower section or an imbedded short base section.  No other type
>  of base is permitted.

     As far as the self-supporting parameters, the latest Rohn info shows that
it will take 1.5 sq.ft. @ 70 MPH and unrated @ 80 MPH. This is from the Rohn
"Manufacturer's Technical Information for Bracketed or Self Supporting
Towers". It's free from TOWER TECH for an SASE.
>  
>  The tower will be 35 foot high mounting only a lightning rod, omni TV
>  antenna, 2M base antenna, 40M inverted V, and one end of an 80 foot
>  inverted L.  I calculate 1.35 sf wind load--all round section.  This
>  will comply with Rohn's 80 mph rating.  K7XLC will be quick to point out
>  that my county is a 100 mph zone--information he kindly provided me. 
>  However the only way those kinds of winds occur here is during the very
>  (so far) infrequent hurricanes.
>  
>  I am not concerned about being under the rated wind speed for this
>  county since the property I bought came with a mobile home.  Should
>  winds in excess of 80 mph occur, I fully expect the tower to fall on a
>  vacant lot.  I will definitely not be anywhere near it.
> 
     It's your installation and you're violating the LXC Prime Directive (DO
what the manufacturer says) and I would recommend installing it for safety and
long-term reliability. 30 feet of freestanding 25G is rated at 1.7 sq.ft. @ 90
MPH.  That would make me feel better.

Cheers,  Steve  K7LXC

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